24 PROCEEDINGS OF THE NATIONAL MUSEUM vol.70 



and smaller strobiles. In most cases the lateral margins are rather 

 sharply serrate. In ripe proglottides the uterus occupies practi- 

 cally the entire interior. 



From ring-billed gull {Lotus delawarensis) : 



One strobile, scolex, and anterior end missing, agrees in all essen- 

 tials with those from other gulls. 



Among the strobiles from Laims Philadelphia referred to this 

 species are two, scoieces missing, which may belong to a different 

 species. They are characterized by having the ripe proglottides 

 longer than broad, and attached by a slender anterior pedicel, thus 

 giving a moniliform aspect to the chain (fig. 68). The genital pores, 

 which are irregularly alternate, instead of being near the an- 

 terior end of the strobile, are farther back, although still in front 

 of the middle of the margin. The genitalia are but imperfectly 

 shown. The vas deferens could be traced from a point near the 

 median line to the cirrus-pouch. It lies in more or less tangled coils, 

 of which the more median are the larger, tapering to a slender thread 

 at the cirrus-pouch. The cirrus-pouch is oval-elliptical, thin walled, 

 and contains a few loops of the vas deferens. The relative position 

 of the ovary, vitelline gland, and testes, so far as could be made out, 

 agrees with that of the other strobiles. Dimensions of larger stro- 

 bile, in balsam : Length 25 mm. ; breadth at anterior end 0.25 ; 

 distance to first distinct segment about 0.42 ; length of first segment, 

 approximately 0.02, breadth 0.31; ripe segments 20 mm. from 

 anterior end, length 1, breadth 0.7; last segment, length 1.12, 

 breadth 0.66. 



KECORD OF COLLECTIONS 



All from "Woods Hole region; collections in all months, except 

 July and August, made by Vinal N. Edwards. 



Larus argentatus: 



1903, November 16. — Two strobiles and six fragments. 



1903, November 21. — Two with scoieces. 



1904, December 3. — One, length, in formalin, 24.5. 

 1906, February 6. — One, scolex missing. 



1906, February 12. — A few fragments, no scoieces. 



1907, February 28, — Few, number not recorded; no scolex. 

 1912, February 19.— One. 



1912, November 13. — Fragments, longest 34 mm., no scolex. 



1913, January 8, — Many fragments, 14 scoieces. 

 1913, April 28. — Few fragments, 2 scoieces. 

 1913, November 17. — One, length 70 mm. 



1913, December 31. — One strobile with scolex, length 130 mm. 



